NHTSA Drafts Rule for 12.8-Volt LED Systems and Cyan Lights

The National Highway Traffic Safety Administration (NHTSA) has proposed a rule requiring a specific voltage standard for modern vehicle lighting. The agency wants to update the current 12.8-volt testing standard to allow manufacturers to build around LED systems without facing administrative hurdles.

In a release issued today, NHTSA outlined amendments to Federal Motor Vehicle Safety Standard No. 108. The proposal targets autonomous vehicles by setting federal requirements for color, brightness, and placement of marker lamps. The agency specified that these lamps would be cyan, a blue-green color distinct from the red, amber, and white lights already used for braking, turn signals, and emergency vehicles. According to the agency, this color would clearly signal to law enforcement and other road users when an automated driving system is operating the vehicle.

The rule makes the cyan lights optional for manufacturers. However, if a company chooses to install them, it must use the consistent configuration outlined in the federal standard. This approach aims to prevent a patchwork of different colors and signals across the industry. The proposal also removes requirements for physical controls that do not function in a driverless car, such as hazard switches, manual beam shifters, and turn levers. NHTSA is also considering dropping rules that dictate the relative position of high-beam and low-beam lights.

Mercedes-Benz previously received state-level approval for turquoise lights on its Level 3 Drive Pilot vehicles, though the company later shifted to a Level 2++ system. NHTSA now seeks a national standard that companies like Waymo, Nuro, and Zoox, along with automakers including GM and Mercedes, can adopt. The move fits into a wider Department of Transportation push to speed up the deployment of autonomous vehicles by making it easier to build cars without traditional human controls like steering wheels and pedals.

Existing rules remain in effect until the new standard is finalized. Last month, NHTSA opened an audit query into the Tesla Cybercab. The agency is examining the technical data Tesla used to certify the vehicle, which lacks sideview mirrors, pedals, and a steering wheel required under current federal standards.